Neck pains

So I bought that Specialized HardRock and I love it (I think, never really had anything to compare to it). The only thing is that while I'm riding, the back of my neck where my neck meets my shoulders usually starts to hurt. Probably from being hunched over and looking up for hours at a time. Is this something that I will just get used to eventually or what. Im about 6'1 210 pounds. I bought a 19" frame. Also the fact that my ass is freakin killing me. But I'm told I'll get over that.
Sorry I don't have anything exciting like a bear chasing me but I did see an angry rabbit today.
Cheers

I think it's a situation where you body is probably not used to riding with your head up for extended periods of time. If it DOESN'T go away, visit your LBS where you bought your bike and ask them to look at your position on the bike. You may be too stretched out as mentioned!

L8R

"Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming, "WOW, What a Ride!" - unknown
"Your Bike Sucks" - Sky Yaeger

Same as mael and a2psyklut ... stand up from time to time and get off your bike regularly between breaks... also move ur head around abit when ride.... not sure if your doing any of this but u should try it and see if any of it works